A Sub-Zero refrigerator’s near-silent operation is one of its defining characteristics, making any freezer noise stand out. What does it mean if your Sub-Zero refrigerator freezer makes noise when door is closed? A loud humming sound usually indicates an evaporator fan motor issue. Use these troubleshooting tips to determine the problem when your Sub-Zero refrigerator freezer makes noise.
What To Do When Your Sub-Zero Refrigerator Makes Noise
How do you know the evaporator fan is at fault when your Sub-Zero refrigerator freezer makes noise? Open the freezer and refrigerator doors. If the refrigerator noise stops when the freezer door is closed, the freezer evaporator fan is responsible. Common freezer problems, like warming temperatures and food defrosting, are also signs of a malfunctioning fan. Here’s how to determine if the motor is to blame or if the fan blades are hampered by an obstruction.
Evaporator Fan Motor
The freezer’s evaporator fan plays a crucial role in producing cold air. As refrigerant runs through the evaporator coils, the fan, positioned right next to them, helps cool the refrigerant, supplying the freezer with cold air. If the fan’s motor is failing, it will make a loud Sub-Zero humming noise. Since the fan doesn’t run when the door is open, you’ll find your Sub-Zero freezer noisy when door is closed.
To confirm that the fan motor is faulty, it should be removed and tested with a multimeter. We recommend that only an experienced DIYer or a professional repair service perform this assessment.
Here’s how to check the evaporator fan motor with a multimeter:
- Consult your Sub-Zero user manual to determine how to access the fan. Most are located behind a rear panel in the back of the freezer.
- Disconnect the fan from its bracket and wire harness.
- Set the multimeter to its ohm setting and touch each tester to each of the fan’s terminals.
- If the multimeter shows a resistance reading of over 100 ohms it means that the motor is failing and the fan should be replaced.
If the fan continues to operate loudly and the motor isn’t at fault, the fan blades may be obstructed by accumulated ice. Given the evaporator fan’s location in the rear of the freezer compartment, icy buildup can collect and prevent the fan blades from rotating. When this happens, you’ll find your Sub-Zero refrigerator freezer makes noise that sounds like gurgling.
If the fan blades are iced over, Sub-Zero suggests manually defrosting the freezer to melt the buildup. Check your user manual to determine the right defrosting process for your model refrigerator. Some enable you to defrost specific sections at a time to avoid warming the entire refrigerator.
A Sub-Zero refrigerator freezer makes noise if the evaporator fan is obstructed by a foreign object as well. If stored food is pushed against the rear of the freezer, packaging may find its way behind the panel and obstruct the fan. In other instances, the fan may have shifted and is rubbing against another component. In both cases, you’ll notice the fan making repeated knocking sounds as the blades hit the obstruction.
Check the fan blades for blockages and try turning them by hand. If the fan blades don’t turn freely or an obstruction can’t be removed, the fan must be replaced.
The certified technicians at Dave Smith Appliance can help with any Sub-Zero freezer repair. Schedule your service with us today!